ARI-500 Automatic Band Switch for ALS-500/600
Instruction Manual
6
The Yaesu FT-450/950 transceivers provide Band Data, ALC, and AMP Keying from a 10-pin MiniDIN connector on the back of
these radios. These connectors are very difficult to find, therefore it is best to purchase the Yaesu CT-118 Band Data cable (~ $40
from most suppliers), and then construct the cable below to interface from the CT-118 to the ARI-500.
Interfacing to the Elecraft K3 Transceiver
The Elecraft K3 outputs band information using the standard 4-line BCD format. Since about SN2370, all K3 radios have pull-up
resistors on the K3 Band Data lines (required). Check the K3 modification page at
www.elecraft.com
for the modification for earlier
K3 radios.
Connection
ARI-500 Radio Input
K3 Accessory
Socket
Band Data A
Pin 7
Pin 13
Band Data B
Pin 6
Pin 3
Band Data C
Pin 5
Pin 9
Band Data D
Pin 4
Pin 14
Amp Key / TX GND
Pin 2
Pin 10
Ground
Pin 1
Pin 5
Interfacing to Kenwood Radios
The Computer port (CAT) is used to retrieve the frequency of the radio. When the ARI-500 is first turned on, the “Auto Information”
(AI) command is sent to the radio. This command causes the Kenwood radio to output the state of the radio (frequency, mode, etc)
anytime the state has changes. The ARI-500 then uses the frequency to determine the appropriate band and then selects the correct
antenna. The diagram below shows how to connect a Kenwood radio with a DB-9M COM port to the ARI-500.
Note that pins 7 and
8 (RTS, CTS) on the Kenwood port must be connected together.
This ensures that the Kenwood will send the status information to
the ARI-500. There is one second delay from when the status of the radio changes until it is sent out over the serial connection. The
Remote port on the back of Kenwood radios has the amp-key line needed for the ARI-500, and the ALC input from the amplifier if
you wish to use it. Refer to the Kenwood manuals and turn on the amplifier keying relay and set the BAUD rate to 9600.
8
7
6
5
4
3
2
1
15
14
13
12
11
10
9
DB15-S
Solder-cup View
1 2 3 4 5 6 7 8
Radio Input
Band A
Band B
Band C
Band D
TX GND
GND
FT-450/950
(Intfc to CT-118)
8
7
6
5
4
3
2
1
15
14
13
12
11
10
9
Band1
Band0
Band2
Band3
GND
1 2 3 4 5 6 7 8
AMP KEY OUT
K3 Interface
HD15-S
Solder-cup View
K3 Accessory Connector
